June 30, 2008

For 10 years, scientists have been waiting for the outcome of a global examination of the habits of thousands of brain cancer patients to explore whether there are links between cellphone use and brain tumors.

But now the findings of the euro 15 million, or $24 million, Interphone study are stalled, caught in an international rift among prominent cancer researchers who are divided about how to interpret the risks of radio-frequency radiation emitted by mobile telephones.

The research group's manuscript of results has drifted for almost three years among scientists in Europe, Israel, Japan and Canada without publication. Some of the researchers are barely on speaking terms, according to some participants. And there is the prospect of further delays because of an ongoing general debate about whether or not cancer patients accurately report their mobile telephone use.

"There seems to be a split," said Lennart Hardell, a participating Swedish cancer specialist who said the divisions focused on whether the faulty memories of brain cancer patients skewed the results of the study. "It's not fair to the public. This has been paid for by taxpayers and they have a responsibility to show the results."

Many of the individual countries involved in the study have already started to release results, some of which have shown increased risk of brain tumors for heavy users - those who have used their cellphones for more than 10 years on the same side of the head. But since national samples are small, the information is not considered as significant as the pooled analysis of the 7,400 patients in the study with tumors in the head and neck area in the study.

Until the Interphone study is published, institutions like the World Health Organization and the European Commission have cautioned that conclusions about possible cancer risks cannot be drawn. But others, in the meantime, are defining the risks - from a hoax video clip that circulated millions of times on YouTube this month showing four ringing mobile telephones popping kernels of corn, to a manifesto issued by French scientists in the same period urging cellphone users to take precautions with hands-free kits.

Michael Milligan, the secretary general of the Mobile Manufacturers Forum, said that cellphone makers were disappointed by the delays of the Interphone study, which it helped to finance.

"We've heard that they can't agree on a manuscript and that's essentially where it comes down to," he said, adding, "We certainly have been encouraging the principle investigators to resolve whatever issues they need to get results to the public."

The GSM Association, a global trade organization of mobile operators, and the forum, which includes Nokia and about a dozen other manufacturers, contributed more than euro 3.5 million to help finance the project. The European Commission also helped fund the project with contributions passed through the International Union Against Cancer to create a barrier between the mobile phone industry and scientists.

The final report was scheduled to be published in 2006, but as time has dragged on, the director of the Interphone study, Elisabeth Cardis, has left her post at the International Agency for Research in Cancer in Lyon, which was coordinating the project. Now at the Center for Research in Environmental Epidemiology in Barcelona, Cardis has a standard answer when questioned about when the draft manuscript will be submitted for publication: "hopefully quite soon."

"It's true that the interpretation isn't clear," she said. "Basically what we've done for the last two years is to try and just tease out the results."

Some of the delay, she added, was caused by the additional research that she was involved in to test how cancer patients, as compared to a control group, recalled past phone use. Those results, published this year, showed that cancer patients and control group users tended to underestimate the number of their calls while overestimating the duration of calls.

Some of the strains and animosity surfaced this month at the annual meeting of the Bioelectromagnetics Society in San Diego, according to Louis Slesin, the editor of Microwave News, a trade journal in New York that tracks mobile telephone health issues and who attended the conference where many of the key researchers gathered for a panel discussion on brain tumors.

"There's some really bad blood between various teams," he said. He noted that there were divisions between the Israeli and Australian researchers, who have publicly urged people to moderate their use of mobile telephones, and researchers from England and Germany, who are wary that the data could be skewed by "recall bias," or the faulty memory of cancer patients.

Joachim Schuz, a cancer researcher who led the German study of cancer patients, dismissed the strains. He said that he expected the results to emerge in six months if the manuscript is submitted in the autumn.

"Of course there are discussions going on," he said. "That's still different between people not talking to each other and people who have different opinions."

Schuz said he believed the evidence was convincing that there was no risk from short-term mobile telephone use although uncertainties remain for long-term use.

"That is why it's so important to have extra information and everybody is working hard to get it out," he said. "I'm still talking to all of them. And we even met for dinner."

Anthony Swerdlow, the scientist who led the British study for Interphone, declined to comment about "unpublished materials or my views about them."

"This would not be right to the other co-authors and to the unpublished nature of the material," he said.

While the manuscript remains unpublished, speculation has increased about the actions of some scientists who have spoken publicly about applying caution. The latest one to speak out was the lead researcher, Cardis, who was asked to sign a manifesto this month urging restraint by French scientists.

She declined to sign, to avoid taking sides. But she did respond to questions from Le Monde, on the same theme. She continues to suggest cautious use.

"I would concur with the idea of limiting the use among young people, first of all because through out their life they are going to be using a phone a lot more than all of us," she said during an interview, adding. "but I would certainly not ban phones, because they are too useful."

Some critics of the delays said they worried that the backstage disagreements of scientists could ultimately weaken the ultimate impact of the study.

Cindy Sage, who helped write a report with several scientists this year in the United States which reviewed existing studies on mobile telephone risks, said that she attended the meeting in San Diego where scientists discussed two circulating versions of the Interphone manuscript.

"This enormous project may come to nothing but ambiguous results," she said. "It sounds pessimistic at this point. What I worry about is that the study will be publicized as an 'all clear.' When in fact the study failed to do a good enough job to know."